Storage tank for volatile gases and liquids



y ,1933. J. H. m ws 1,906,685

STORAGE TANK FOR VOLATILE GASES AND LIQUJEDS Filed Feb 6, 1928 6'TTOIQ/VEYS.

' dition to being cap I height of the space I 45 transverse sectionalPatented May 2, 1933 UNITED STA JOHN H. WIGGINS, O1 TULSA, OKLAHOMA.

jppllcatlon filed February This invention relates to large metal tanksof the kind that are used for storing volatile liquids and gases, which)tanks are used extensively'in the oil fields for storing 5 oil and oftenhave a diameter'in excess of One object of my invention is to provide astorage tank of the type mentioned that is equipped with a. metal roof,which, in1'adable of moving bodily vertically relatively to the;stationary side wall of the tank, is provi ing means that'maintains theroof in pr oper balance. 1

Another object is to provide a tank of great capacity closedby a metalroof that is capable of moving vertically relatively to the stationaryside wall of the tank so as to vary' the between the 1'00 and the bottomof the tank, and is also capable of flexing vertically so as to functionor act as a so-called breather type roof.- Other objects and desirablefeatures of my invention will be hereinafter pointed out.

To this end I have devised a storage apparatus of the general typementioned, that is composed of a tank ope'n'at'is upper end, a roof forsaid tank formed of metal and 39 combined with the tank in such a waythat said roof is capable of moving vertically relatively tothe sidewall of the tank to vary the height of the space between the roof andthe bottom-of the tank, a depend- 15 storage ing portion attheperipheral edge of said ,as to'constitute bounded by the stationaryside .roof submerged in liquid so a liquid seal for the space roof andthe bottom and wall of; the tank, and a means combined 40 with said roofthat will impart additional stabilityv to the roof or counteract strainsor forces tending to throw the roof out of balance. p

Figure 1 of the drawing is a vertical viea of a liquid storage tankconstructed in accordance with my present invention, illustrating heroof of the. tank flexed upwardly and raised slightly so as toincreaseof. the vapor space the volume between the-1' surface of dedwith a stabiliz-- whose upper end is 8,1928. Serial mi. 252,408.

the liquid in of the roof;

Figure 2 is a similar view, the roof of the tank in TBS PATENT OFFICEthe tank and the underside illustrating an' elevated position andfloatingupon or sustained by the liquid in the tank.

Figure 3 is a view, partly in top 'plan and partly in horizontalsection, line 3-3 of Figure 1.

In the preferred f0 herein illustrated the tank is a side wall thatcomprises a er portion 1 and a vertically portion 2, the space portionsbeing sealed liquid w contained in a the stationary portion 1 andarranged preferably,

taken on the mm of my invention provided with stationary low- -movableupper or joint between said by a body of sealing trough 3 carried by ofthe side wall oncthe outside of same with the top edge of said troughterminating at a p top edge of said stati oint considerably above the 10onary wall portion 1.

The roof or top A of the tank is formed from metal sheets or platesconnected toether in such a way as to form a one-piece imperforatediaphragm whose peripheral edge is rigidly connected by a gas-tightjoint 4 to the vertically-movable upper por- ,tion 2 of the side wall ofthe tank. Hence,

the-roof may be said to constitute a ly-movable closure tank, combinedby for the upper end of the a liquid seal with the verticalstationaryside wall of the tank. Said roof can either be constructed in the formof a rigid member -order to prevent rain trough 3, which holds a hood 5is provided for'said trou hood is herein illustrated as being asubstantially inverted, cha

form of a limber sheet, or it can be constructed in the or structure. Infrom entering' the the sealing liquid as,

h, which ormed by nnel-shape member connected to the movable portion 2of the side wall and arranged so. "as, to prowall of the trough 3.

A supporting structure, designated as an entirety by the referencecharacter ranged inside of the tank so' asto sustain when the levei ofthe li uid in ject laterally and downwardly over the outer -95 B, is arte staor when 100 the upward pressure exerted on the underside of theroof by the gas in the space between the roof and the surface of theliquid in the tank is less than the weight of the roof, said supportingstructure B also being utilized to sustain the plates from which theroof A is constructed during the operation of fabricating .the roof andconnecting it to the depending sealing element at the peripheral edge ofthe roof that constitutes the mova-ble portion 2 -of the side wall. Thesupporting structure B can be formed in various ways, but it is hereinillustrated as comprisinga center post 6 that sustains the inner ends ofa plurality of radially-disposed supporting members 1 7 sustained attheir outer ends by an angle 8 or brackets connected to the inner faceof the stationary portion 1 of the side wall and arranged eitherhorizontally or with their inner ends inclined downwardly slightly. Aspreviously stated, means is provided for imparting sufficient stabilityto the roof to insure its remaining in a properly balanced condition,

. and thus successfully performing the funcit is employed. In the formtion for which I of my invention herein illustrated the-means Justreferred to is formed by suitable springs 9 that are connected at theirlower ends to laterally-projecting brackets 10 on the stationary sidewall 1 of the tank and connected in their upper ends to the hood 5 orsome portion of the roof, in such a manner that they counteract forcesor.strains exerted on the roof in a direction roof out of balance.

other means could be substituted for the springs 9 without departingfrom the spirit of my invention. I prefer to construct the roof A in theform of a limber sheet which is capable of flexing upwardly a limiteddistance relatively to'the portion 2 of the side wall of the tank towhich it is connected, so as to function as a breather type roof, andautomatically increase the vapor space above the surface of the liquidin the tank.

Accordingly, if the gases in the space be tween the surface of theliquid in the tank and the underside of the roof expand, the roof willflex upwardly, as shown in Figure 1, sufliciently to provide for theexpansion of the gases,.and thus prevent the roof from being subjectedto destructive strains. If the upward pressure exerted on the undersideof the roof is unequal, for example, if it is greater at the right handside of the tank, looking at Figure 1, the right hand side of the roofwill start to rise, thereby increasing the tension on the springs 9connected to this portion of the roof, with the result that the upwardmovement of this portion of the roof will bemqmentarily checked orarrested until the left hand side of the roof rises sufliciently toplace the springs connected to same under substantending to throw theObviously various that rain falling tially the same tension. It willthus be seen that in a tank roof of the construction above described theroof is capable of flexing in a direction to automatically increase thevolume of the vapor space in the tank; the roof is also capable ofbodily moving upwardly relatively to the stationary portion 1 of theside wall of the tank, thereby increasing the vapor space still more,and during said bodily. upward movement, the roof is maintained in asubstantially horizontal position and is prevented from being thrown outof balance by the tension devices 9, or other means employed tostabilize the roof and maintain it in proper balance. When the roofrisesso highthat the depending sealing element on the roof that constitutesthe movable portion 2 of the side wall, nearly leaves the sealing liquidin which it is submerged, then some of the gas on the underside of theroof will escape underneath said movable sealing element or side .Wallportion 2, thereby preventing an abnormal pressure or dangerous pressurefrom being created .in the tank. The roof can be provided with aconventional vacuum relief valve D that will open automatically, andthus admit air to the tank when liquid is being drawn out of the tank.

In view of the fact that the roof A is capable of moving bodily upwardlyor downwardly a limited distance relatively to the stationary portion 1of the side wall of the tank, it is possible to fill the tank withliquid to a height or level above the top edge of the stationarysidewall l of the tank. At such times the roof floats upon and issustained by the liquid in the tank, as shown in Figure 2, and thedepending portion at the peripheral edge of, the roof is sealed by theliquid on which the roof floats.

The tank can be equipped with any suitable kind of device or apparatusfor draining the top surface of the roof. In Figure 2 of the drawing Ihave illustrated asiphon drain 11 leading from the top surface of theroof and extending laterally and downwardly .over the hood .5 attachedto the movable portion 2 of the side wall of the tank. In Figure 1 ofthe drawing I have illustrated the tank equipped with a gravity drainformed by a flexible drain pipe 12 leading from the top side of the roofthrough the liquid in the tank and extending to the outside of the tankatroa point near the'bottom of the side wall of same. A drain of thekind shown in Figure 1 will not function when the roof is in an upwardlyflexed condition, as shown in Figure 1, but in view of the fact onto theroof causes the gases in the tank to cool and contract, therebypermitting the roof to flex downwardly, any rain water which falls onthe top side of the roof will be carried. off of'same by the drain pipe12 rapidly enough to eliminate ;he possibility of the roof being sunk byin excessive rain load, I

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent, is:

1. A tank for. storing gases and volatile liquids provided with a sidewall comprising an upper portion that is capable of moving vertically alimited distance relatively to the stationary lower portionof the sidewall, means for sealing the joint or space between said movable portionand stationary portion, a top or roof connected to the movable portionof the side wall, and a resilient means combined with said roof forcounteracting unequal forces or loads exerted on the roof tending tothrow it out of balance.

2. A tank for storing gases and volatile liquids provided wi h a sidewall comprising an upper portion that is capable of moving vertically alimited distance relatively to the stationary lower portion of the sidewall, means for sealing the joint or space between said movable portionand stationary portion, a top or root connected to the movable portionof the side wall, and tension springs connected with the peripheralportion of the roof and with the stationary portion of the side wall ofthe tank for exerting a down ward force on the roof.

3. A tank for storing gases and volatile liquids-provided with a sidewall-that comprises a stationary lower portion and an I liquids,

wall, a metal roof arranged so as to be capupper portion that isvertically relatively to said lower portion, means for preventing thecontents of the tank from escaping through the joint between the movableand stationary portions of the side wall, a supporting structure in thetank arranged adjacent the top edge of the stationary portion of theside of the side wall and normally sustained by said supportingstructure, said roof being capable of flexing upwardly to increase thevolume of the vapor space in the tank, and a resilient means combinedwith the roof which tends to prevent the upper portion of the side wallfrom moving upwardly but which is capable of permitting said upperportion to bodilymove with the roof under certain conditions.

4. In a tank for storing gases and volatile the combination of astationary side able of moving bodily vertically relatively to saidstationary side wall and constructed so as to be capable offlexingupwar-dly to inthe vapor space in the space or joint'between theflexible roof and said stationary side wall.

Y- 5. In a storage apparatus, of a. tank provided wall, a metal roof forsaid capable of moving wall, a flex-- ible roof connected to the movableportion' the combination with a-stationary side tank arranged so as to'be capable of moving bodily towardsand away from the bottom of the tank,said roof being constructed so as to be capable offl'exing upwardly anddownwardly to vary the volume of the vapor space of the tank, and a liuid seal for the peripheral edge of said roo 6. In astorage apparatus,the combinaside wall, a metal roof adapted to float on the liquid in thetank and move bodily rela-'- tively to said side wall as the level ofthe liquid in the tank-varies, also said roof being constructed so as tofunction as a breather type roof, and a stabilizing means that isadapted to exert pressure on the roof in a substantially verticaldirection and in opposition to forces or pressures tending to throw theroof out of balance.

7. In a storage apparatus, the combination of a tank provided with astationary side wall, a metal roof adapted to float on the liquid in thetank and move bodily relatively to said side wall as the level of theliquid in the tank varies, also said roof being constructed so as tofunction as a breather ty roof, a depending sealing element on t e roofnormally submergedin the 'li uid on which the roof floats, and a stailizing means for exerting pressure on the roof in a substantiallyvertical direction, in opposi .tion tocounteracting forces or pressurestending to throw the roof out of balance.

JOHN H. WIGGINS.

tion of a tank provided with a stationary-

